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PLATING OVER SG IRON

WE ARE BASICALLY A CASTING MANUFACTURER PRODUCING AUTOMOTIVE COMPONENTS AND FOR FEW ITEMS WE DO USE SG IRON NICKEL PLATED CHAPLTES FOR SUPPORTING THE CORE{PLEASE NOTE SMALL STEEL NAILS ARE USED TO ATTACH THE CHAPLET WITH MOLD}.IN DOING SO, VERY OFTEN WE COME ACROSS INCOMPLETE FUSION OF CHAPLET AND HENCE LEAK ON TESTING DUE TO MINOR POROSITY CAUSED. WILL You PLEASE TELL, 1.CAN COATING BATH OR ASSOCIATED PARAMETERS HAVE ANY APPRECIABLE INFLUENCE ON IT? 2.WHICH IS SUITABLE, EITHERLESS OR ELECTROLYTIC PLATING?

KASI SP
ENGINEER - CASTING MANUFACTURING - COIMBATORE, TAMILNADU, INDIA
2005

I didn't understand your question Mr. Kasi. What do you expect from your proposed plating and what do you want to plate, the whole casting, the chaplet, the nails? Is it the idea to make the whole part impervious, to assure a complete melt of the chaplet, to eliminate gassing or what?

Guillermo Marrufo
Monterrey, NL, Mexico
2005

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2005

Dear Mr Kasi,

Neither Electroless nor Electroplated Nickel as a release agent will have an impact on your casting quality. You may want to look at Teflon Coating your chaplets and doing away with nails to hold them in place.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

We use electroplated SG (spheroidal graphite cast iron - one form of cast iron grade) iron chaplet for supporting cores (core- used to retaining desired shape or gap) in sand molds. steel nails are used to anchor the chaplet with the mold. So, only the chaplet is given plating to prevent rust formation and further associated undesirable effects that may rise defects in casting. Now, I do hope I have clearly defined the state and you may please refer the aforesaid question.

KASI
FOUNDRY DIVISION - COIMBATORE, TAMILNADU, INDIA
2005

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2005

Dear Mr Kasi,

In other words both are suitable, EN will be costlier but have better dimensional control, Electrolytic will be cheaper with less accuracy.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

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The use of SG Iron for the chaplet is to make sure its total dissolution in the parent metal. The coating of nickel is for protecting the chaplet from rust?. Perhaps a chaplet of evaporative polystyrene may do the trick. More useful if the core is being held in place against gravity.
good luck.

Shivanand Gaitonde
retired - Pune, Maharashtra, India
2005